Hispeedmailer.com

Hispeedmailer.com/hispeedmedia.com is based in Glendale CA; they buy service from Relaypoint, who give their contact info as a PO Box in Glendale. Next up the food chain looks to be Level 3. Best to block by IP. This /26 may be a tick large, but the reverse DNS is funky and 64.32.34.0/26 is the smallest block that covers the email sources.

Received: from localhost (127.0.0.1) by skipper.krusty-motorsports.com with
  POP3 for <postmaster@skipper.krusty-motorsports.com>; 11 Feb 2002 14:36:03
  -0000
Return-path: <offers@wowdeals.net>
Envelope-to: rwelty@KRUSTY-MOTORSPORTS.COM
Delivery-date: Mon, 11 Feb 2002 09:37:36 -0500
Received: from [64.32.34.14] (helo=hispeedmailer.com)
        by krusty1.krusty-motorsports.com with smtp (Exim 3.952 #2)
        id 16aHaK-0005lH-00
        for rwelty@KRUSTY-MOTORSPORTS.COM; Mon, 11 Feb 2002 09:37:36 -0500
Received: (qmail 25369 invoked by uid 0); 11 Feb 2002 14:31:03 -0000
To: rwelty@KRUSTY-MOTORSPORTS.COM
Date: Sun, 10 Feb 2002 23:30:00 -0800
Reply-To: Exclusive Offers<offers@wowdeals.net > 
From: Exclusive Offers<offers@wowdeals.net > 
Subject: Hi Speed Media Wants You To WIN! 
MIME-Version: 1.0
Content-type: text/html
Message-Id: <E16aHaK-0005lH-00@krusty1.krusty-motorsports.com>